v2: Problems with Sync mode when there is no network connection

[zeus-web]

I use Silverbullet on an Android phone (among different desktop systems). But I run into problems as soon as there is no network connection. I thought, that should be no problem with sync-mode.

I tried with different browsers: Chrome, Firefox and DuckDuckGo browser (where I'm not sure on which it is based).
I tested Silverbullet is either opened via browser directly or is "installed as app" (from the browsers).

As long as there is a network connection everything is fine. However, if I switch to "Airplane mode" on the mobile, the trouble begins:

Directly after switching to Airplane mode, most of Silverbullet is working fine. However, if I open a tag-page ("tag:blabla") page, it takes about 30 seconds until it is displayed. That happens on every tag page.
Switching to other pages is no problem, however. Even pages with queries or scripts on them.

But even worse:
As soon as I "reload" the browser or close the "app" and reopen, I only get a white page.
If I put the app in background and foreground again, there is no problem

As there is no GUI element at all, no button or whatever, I can't try to "reload UI" or "reload system", either.

Looks like Silverbullet needs a connection on first start after the page/browser/"app" was closed once?

During my tests, I once saw a popup saying "could not load config" and after that a black page saying "offline", only.

As far as I understand, working completely offline (at least from time to time) should be fine...

[zeus-web]

Well... After some experiments I found out, that this behavior is NOT the same on latest stable with sync-mode enabled:

With latest stable: after the app was closed and reopened, I see the blank page, but this time with the button-bar showing (but not working).
After I wait about 10 seconds my testpage shows up . Looks like it tries to connect until a timeout occurs (I'm fine with that).

However in v2 the page never comes up, stays a white page

[iamdangry]

Looks like the clientConfig key isn't being set reliably (or at all) in the datastore on the initial load (or it is taking its sweet time). On my desktop, I've noticed on initial load the key doesn't get set, but after 2-3 (sometimes more) refreshes it sets and then offline mode works. Haven't managed to get offline mode to work on any iOS device though. Hopefully Zef has an idea on how to fix

[zefhemel]

Ok, there's different issues here but I'll look into it.

[papadopa]

I am facing the issue of the app not initializing if I'm offline. If I open it while online and then lose connectivity, it's ok.

Looking at the code a bit, I don't think it can initialize offline (assuming my read is correct):

• https://github.com/silverbulletmd/silverbullet/blob/main/web/boot.ts#L8 tries to fetch a client config which involves a /.config request
• the service worker intercepts the fetch call which doesn't hit the cache (https://github.com/silverbulletmd/silverbullet/blob/main/web/service_worker.ts#L13); side question why not have /.config cached and refreshed whenever online?
• crucially though, the datastore isn't available yet (one needs a client config to initialize it), so we actually resolve into actually trying to fetch over the network: https://github.com/silverbulletmd/silverbullet/blob/main/web/service_worker.ts#L100

This is fairly easy to replicate (I'm working with a ~9d docker image btw though the problem has been persistent for a while and I didn't see any recent activity that would change the behaviour).

[flowkclav]

I also ran into this issue while working on other stuff and also came to the same conclusion.

I wrote a hack to work around the problem until a proper solution is found.

If you're interested/curious: main...flowkclav:silverbullet:offline-hacks . (Like I said this is a total hack and not intended to be a fix worthy of a PR - also ignore the other thing about reacting differently to a 403, that's just for the way I'm setup. I wasn't really planning for anyone else to see this branch :) )

[papadopa]

@zefhemel maybe a question for you on this, to what degree is it required for the indexedDB db name to be derived from the client config (specifically the hashed space path). Would just using 'silverbulletv2' not do it? That way we could break the dependency of initializing the datastore and fetching /.config for instance.

Otherwise it seems that storing a copy of the client config (in localstorage or another indexeddb I guess) might be the way to go (not sure if caches are ok, it seems we don't control their lifetime).

Depending on this, I might be able to take a stab at a PR.